This project proposes to examine the interactions between personality variables such, as anger and hostility, and a number of physiological variables, including both natural and acquired immune responses, plasma lipids, and stress related hormones. It is hypothesized that anger expression will affect both immune functions and lipid levels, and that these responses may be mediated through changes in stress hormones, particularly peripheral norepinephrine (NE) and epinephrine (E). It is also expected that psychosocial variables, such as final exams or the absence of social support, could increase physiological responses and state anger. Pilot results partially support these hypotheses, as high levels of anger-out were negatively related to natural cytotoxicity during final exams, while anger-control was correlated with elevated lipid levels, and moderate anger-control was associated with lower lipid levels. The present project proposes to extend the previous findings by including additional immune measures, repeated blood pressure measurements, measures of both state and trait anger, indices of social network size and satisfaction with social support, and more detailed examination of dietary and lifestyle variables. The subject in this experiment will be first and second year medical male and female students. The protocol calls for an initial battery of psychological questionnaires examining stable personality attributes, current perception of environmental stressors, assessment of current mood, social support network size and satisfaction with social support. Blood samples will be processed immediately for immune functions and cholesterol levels, while plasma will be stored at -70 C. for later hormonal assays. Brief questionnaires will be given during the mornings of blood sampling concerning current mood, perceptions of stress, and dietary and lifestyle variables. It is thought that information gained regarding the effects of different emotional styles and levels of anger expression or anger control, could have considerable health consequence.